1. Field of the invention
The present invention relates to a liquid crystal display device, and more particularly to a technique which is effectively applicable to a liquid crystal display device which arranges a bus line outside a display region.
2. Description of Related Art
Conventionally, a liquid crystal display device has been popularly used as a display for a television receiver set or a personal computer (PC), a display of a mobile phone terminal or a personal digital assistant (PDA) or the like.
The liquid crystal display device is a display device which includes a liquid crystal display panel sealing a liquid crystal material between a pair of substrates. Here, one substrate out of the pair of substrates includes, for example, a plurality of scanning signal lines, video signal lines which three-dimensionally intersect the plurality of scanning signal lines by way of an insulation layer, and a TFT element and a pixel electrode which are arranged in each pixel region surrounded by two neighboring scanning signal lines and two neighboring video signal lines. The substrate which includes the TFT elements and the pixel electrodes is generally referred to as a TFT substrate.
Further, a conductive layer which is referred to as a bus line may be arranged on the TFT substrate outside a display region which is constituted of a plurality of pixel regions, for example (see patent document 1, for example).
When the liquid crystal display panel adopts a lateral electric field driving method such as an IPS (In-Plane Switching) method, for example, counter electrodes (also referred to as common electrodes) may be also formed on the TFT substrate. Here, the TFT substrate includes the bus line which is electrically connected with the counter electrodes outside the display region.
Further, when the liquid crystal display panel adopts a vertical electric field drive method such as a TN method or a VA method, holding capacitance lines for forming holding capacitances (also referred to as storage capacitances) may be formed on the TFT substrate. Here, the TFT substrate includes the bus line which is electrically connected with the holding capacitance lines outside the display region.
[Patent document 1] JP-A-2003-156763